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Author Topic: C1 and C2 DOUBTS HERE!!!!!  (Read 98325 times)

Offline wakemeup

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Re: C2 DOUBTS HERE!!!!!
« Reply #150 on: June 03, 2010, 05:01:58 pm »
Could someone please explain how to do 4b in this paper
http://www.xtremepapers.net/Edexcel/Mathematics/2008%20Jan/6664_01_que_20080109.pdf

I get some of the answers but how exactly do I get all 6? I'm still kinda confused in trigonometric functions. So if anyone could give some notes about how to find other angles after finding the first one through the equation, that would be really helpful.

Thanks
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Offline Ghost Of Highbury

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Re: C2 DOUBTS HERE!!!!!
« Reply #151 on: June 03, 2010, 05:10:15 pm »
Quote from: wakemeup on June 03, 2010, 05:01:58 pm
Could someone please explain how to do 4b in this paper
http://www.xtremepapers.net/Edexcel/Mathematics/2008%20Jan/6664_01_que_20080109.pdf

I get some of the answers but how exactly do I get all 6? I'm still kinda confused in trigonometric functions. So if anyone could give some notes about how to find other angles after finding the first one through the equation, that would be really helpful.

Thanks
i can get 3 values..cud u provide the ms link?
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Offline wakemeup

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Re: C2 DOUBTS HERE!!!!!
« Reply #152 on: June 03, 2010, 05:25:49 pm »
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Offline wakemeup

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Re: C2 DOUBTS HERE!!!!!
« Reply #153 on: June 03, 2010, 05:31:06 pm »
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Offline Ghost Of Highbury

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Re: C2 DOUBTS HERE!!!!!
« Reply #154 on: June 03, 2010, 05:34:43 pm »
sin^2 x = 0.6

sin x = +/- sqrt(0.6) = =/- 0.7745

x = sin(-1) 0.7745 = 50.7

180-50.7 = 129.3

x = sin(-1) -0.7745 = -50.7

180 - (-50.7 ) = 230.7

360 - 50.7 = 309.7

answers : 50.7, 129.3, 230.7, 309.7



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Offline wakemeup

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Re: C2 DOUBTS HERE!!!!!
« Reply #155 on: June 03, 2010, 05:41:25 pm »
Quote from: A@di on June 03, 2010, 05:34:43 pm
sin^2 x = 0.6

sin x = +/- sqrt(0.6) = =/- 0.7745

x = sin(-1) 0.7745 = 50.7

180-50.7 = 129.3

x = sin(-1) -0.7745 = -50.7

180 - (-50.7 ) = 230.7

360 - 50.7 = 309.7

answers : 50.7, 129.3, 230.7, 309.7





Thanks. Could you please do the other one too?
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Offline Ghost Of Highbury

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Re: C2 DOUBTS HERE!!!!!
« Reply #156 on: June 03, 2010, 05:43:48 pm »
it isnt loading...taking a hell lotta time...
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Offline Ghost Of Highbury

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Re: C2 DOUBTS HERE!!!!!
« Reply #157 on: June 03, 2010, 05:48:00 pm »
cos 3x = -0.5

y - 3x

cos y = -0.5

y = cos-1 -0.5 = 120
360+120 = 480. 480/3 = 160
360 - 120 = 240 . 240/3 = 80

x = 80
x = 160
3x = 120

x = 40
x = 360-40 = 320

idk how they got 200 and 280 :-/
« Last Edit: June 03, 2010, 06:01:59 pm by A@di »
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Offline Majdovic14

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Re: C2 DOUBTS HERE!!!!!
« Reply #158 on: June 05, 2010, 11:48:15 am »
Guys can anyone post the formula for Area,volume or surface area for the following:
1)cuboid
2)Prism
3)cylinder
4)semi circle
5)Rectangular box
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Offline Ghost Of Highbury

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Re: C2 DOUBTS HERE!!!!!
« Reply #159 on: June 05, 2010, 12:09:41 pm »
1) Cuboid
 
Volume - Lenght*Breadth*Height

Surface area = 2(lb + bh + hl)

2) Prism

 Volume = Area of floor*height

Surface area =  2 * area of base  +  perimeter of base * H

3) Cylinder - Pir^2h (Vol.)

 Surface area --> 2pir^2 + 2pirh

4) Semi-circle - > Area - (pi*r^2)/2

5) Box - if u mean cuboid? answered, if u mean cube - VOlume - l*B*H

Surface area = 4(LB)
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Offline Ibiza279

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Re: C2 DOUBTS HERE!!!!!
« Reply #160 on: June 05, 2010, 09:41:54 pm »
im havin difficulty in math c2 jan 2010 question 8 part c 
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Offline astarmathsandphysics

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Re: C2 DOUBTS HERE!!!!!
« Reply #161 on: June 05, 2010, 10:00:32 pm »
Half hour
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Offline astarmathsandphysics

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Re: C2 DOUBTS HERE!!!!!
« Reply #162 on: June 06, 2010, 07:24:46 am »
the x coordinates of A and B are 2-12/2=6=-4 aand 2+12/2=8

y coordinate of A
(x-2)^2+(y+1)^1=169/4
(-4-2)^2+(y+1)^1=169/4
36+(y+1)^1=169/4
(y+1)^2=6.25 so y=+-sqrt(6.25)-1=-3.5 or 1.5 but y<0 so -3.5
the x coordinates of A and B are 2-12/2=6=-4 aand 2+12/2=8

y coordinate of B
(x-2)^2+(y+1)^1=169/4
(8-2)^2+(y+1)^1=169/4 so 36+(y+1)^1=169/4
(y+1)^2=6.25 so y=+-sqrt(6.25)-1=-3.5 or 1.5 but y<0 so -3.5
A=(-4,-3.5) B=(8,-3.5)

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Offline Ibiza279

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Re: C2 DOUBTS HERE!!!!!
« Reply #163 on: June 06, 2010, 10:56:01 am »
n also question 7 part d of the same paper :3 Thanks !
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Offline astarmathsandphysics

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Re: C2 DOUBTS HERE!!!!!
« Reply #164 on: June 06, 2010, 12:18:38 pm »
Not at home now
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